1,082 research outputs found

    Managing Climatic Risks to Combat Land Degradation and Enhance Food security: Key Information Needs

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    This paper discusses the key information needs to reduce the negative impacts of weather variability and climate change on land degradation and food security, and identifies the opportunities and barriers between the information and services needed. It suggests that vulnerability assessments based on a livelihood concept that includes climate information and key socio-economic variables can overcome the narrow focus of common one-dimensional vulnerability studies. Both current and future climatic risks can be managed better if there is appropriate policy and institutional support together with technological interventions to address the complexities of multiple risks that agriculture has to face. This would require effective partnerships among agencies dealing with meteorological and hydrological services, agricultural research, land degradation and food security issues. In addition a state-of-the-art infrastructure to measure, record, store and disseminate data on weather variables, and access to weather and seasonal climate forecasts at desired spatial and temporal scales would be needed

    Role of Shrubs in Rangeland Based Livestock Production System in Western Rajasthan, India

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    Rangeland covers ~ 51% of the terrestrial surface of the Earth, and supports half of the world‟s livestock. More than 80 % of forage consumed by domestic livestock is supplied by rangelands in Africa and Asia. Hot arid regions of India cover an area of 31.7 million hectares and out of which Rajasthan state constitutes ~ 61.8 % of the entire area. The crop production in this area is low, unstable and risky. Livestock sustains arid farming systems by virtue of their potential to reduce risk, alleviate poverty, important providers of nutrients and traction for growing crops in smallholder systems and the imparting sustainability of household. The hot arid region of Rajasthan has about 29.08 million livestock. Pastures and grazing lands, residential area and wayside grazing lands, crop by-products and residues, fodder crops etc. are the major feed resources. For the small ruminants and camels, the rangelands are the major source of feed supply. Shrubs are vital component of rangeland vegetation and cover \u3e 70 % of desert landscapes from Aravalli to the international border of the Indian part of Thar desert. They are an important source of feed and assure feed availability in a drought situation. They have remarkable morpho-physiological adaptations to different land forms and survive under harsh edapho-climatic conditions. During recent past, a rapid decline population of browse shrubs is noticed due to their over exploitation, destruction of natural habitat, expending irrigation facilities, increasing agricultural mechanization and changes in land use pattern. In the present paper key species, fodder production and nutritive value of shrubs of hot arid rangelands are discussed

    Effects of Carbohydrates on in vitro axillary shoot initiation and multiplication of Bambusa pallida Munro.

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    The purpose of the current study was to optimize the carbohydrate sources and sucrose concentrations for mass clonal propagation of B. pallida. Sucrose in MS liquid medium consisting additives (ascorbic acid, 50mg/l + citric acid, 25 mg/l + cysteine, 25 mg/l) was found to be the best carbohydrate source for shoot induction and shoot multiplication.  NAA 0.25mg/l in combination with TDZ 0.25mg/l in the medium exhibited high frequency shoot induction and NAA 0.25mg/l with BAP 1.0mg/l helped for further multiplication of quality shoots.  IBA pulse treated shoots were rooted in the MS half strength agar gelled medium fortified with sucrose (2%) and glucose (1%). Rooted plantlets were well established in the green house with more than 95% survivability within four weeks period.&nbsp

    Charge Delocalization in Self-Assembled Mixed-Valence Aromatic Cation Radicals

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    The spontaneous assembly of aromatic cation radicals (D+•) with their neutral counterpart (D) affords dimer cation radicals (D2+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation of dimer cation radicals is deliberated with the aid of a series of cyclophane-like bichromophoric donors with drastically varied interplanar angles between the cofacially arranged aryl moieties. X-ray crystallography of a number of mixed-valence cation radicals derived from monochromophoric benzenoid donors established that they generally assemble in 1D stacks in the solid state. However, the use of polychromophoric intervalence cation radicals, where a single charge is effectively delocalized among all of the chromophores, can lead to higher-order assemblies with potential applications in long-range charge transport. As a proof of concept, we show that a single charge in the cation radical of a triptycene derivative is evenly distributed on all three benzenoid rings and this triptycene cation radical forms a 2D electronically coupled assembly, as established by X-ray crystallography

    (7E)-5-Benzyl-7-(2-chloro­benzyl­idene)-3-(2-chloro­phen­yl)-2-phenyl-3,3a,4,5,6,7-hexa­hydro-2H-pyrazolo­[4,3-c]pyridine

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    In the title 2H-pyrazolo­[4,3-c]pyridine derivative, C32H27Cl2N3, the dihydro­pyrazole ring adopts an envelope conformation and the piperidine fused ring a twisted-chair conformation. Two short intra­molecular C—H⋯Cl contacts are observed. The crystal packing is characterized by dimeric C—Cl⋯π inter­actions involving the 5-benzyl ring, with Cl⋯centroid and closest atomic Cl⋯π distances of 3.778 (2) and 3.366 (4) Å, respectively

    The value of multiple data set calibration versus model complexity for improving the performance of hydrological models in mountain catchments

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    The assessment of snow, glacier, and rainfall runoff contribution to discharge in mountain streams is of major importance for an adequate water resource management. Such contributions can be estimated via hydrological models, provided that the modeling adequately accounts for snow and glacier melt, as well as rainfall runoff. We present a multiple data set calibration approach to estimate runoff composition using hydrological models with three levels of complexity. For this purpose, the code of the conceptual runoff model HBV-light was enhanced to allow calibration and validation of simulations against glacier mass balances, satellite-derived snow cover area and measured discharge. Three levels of complexity of the model were applied to glacierized catchments in Switzerland, ranging from 39 to 103 km2. The results indicate that all three observational data sets are reproduced adequately by the model, allowing an accurate estimation of the runoff composition in the three mountain streams. However, calibration against only runoff leads to unrealistic snow and glacier melt rates. Based on these results, we recommend using all three observational data sets in order to constrain model parameters and compute snow, glacier, and rain contributions. Finally, based on the comparison of model performance of different complexities, we postulate that the availability and use of different data sets to calibrate hydrological models might be more important than model complexity to achieve realistic estimations of runoff composition

    Physiological Response to Salinity and Alkalinity of Rice Genotypes of Varying Salt Tolerance Grown in Field Lysimeters

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    Soil salinity and alkalinity seriously threaten rice production in south Asia. Improving screening methodologies to identify sources of tolerance for improved breeding for salt tolerant rice is of continuing importance. Rice genotypes of varying salt tolerance, such as tolerant (T), semi-tolerant (ST), and sensitive (S), were grown in field lysimeters in saline soil of ECe 4 and 8 mS cm-1 and alkali soil of pH 9.5 and 9.8 in North India and analyzed for chlorophyll (Chl), sugar, starch and proline in leaves. Chlorophyll a and b decreased due to salinity in all the tolerance groups. However, Chl a was not much affected but chl b increased with alkalinity. Under high stress both at ECe 8 and pH 9.8 Chl a and b were more in tolerant than in sensitive genotypes. The ratio of Chl a/b was similar in T, ST and S genotypes under salinity stress. Sugar accumulation was higher in T compared to S under normal conditions but under salinity or alkalinity stress the differences were not significant. Leaf starch was highest in T, intermediate in ST and lowest in S genotypes in normal as well as under salinity and alkalinity stress. There was decrease in starch with salinity and alkalinity stress only in T group but not in ST and S group. Proline increased significantly in all the tolerance groups even at low salinity of ECe 4 mS cm-1 or pH 9.5. The salt tolerant genotypes of rice maintained higher levels of Chl a and b, starch and proline under high salinity and alkalinity stress and are the robust criteria for tolerating high salinity and alkalinit

    Genetic variability, genotype × environment interaction and correlation analysis for grain iron and zinc contents in recombinant inbred line population of pearl millet [Pennisetum glaucum (L). R.

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    Micronutrient malnutrition is one of the major health problems, especially iron (Fe) and zinc (Zn) deficiencies that are widespread coupled with inadequate food supply in the developing world. Pearl millet grains are a good source of Fe and Zn elements making it a potential staple crop for overcoming hidden-hunger and micronutrient deficiencies. Breeding pearl millet with high levels of grain Zn and Fe contents represents a major opportunity to enhance the intake of these minerals for poor and malnourished people. A precise understanding of the genetic variability, correlation of mineral nutrients, genotype × environment (G × E) interaction is important for developing improved lines with high Fe and Zn content. To get fair estimates, we used a bi-parental recombinant inbred lines (RIL) mapping population representing F2 phenotypic variance. A total of 317 RILs were evaluated for grain iron and zinc content in two seasons, Summer 2016 (E1) and Summer 2017 (E2). The result from the analysis of variance exhibited a large variability for grain Fe and Zn content across the two environments. The G × E for high grain Fe were significant at P < 0.01. The mean performance across the two environments data for grain Fe ranged from 22.9 to 154.5 mg kg-1 (ppm) and Zn content ranged from 19.3 to 121 mg kg-1. The correlation coefficient for grain Fe and Zn was 0.9, and 0.8 and across the two (E1 and E2) environments. The value of correlation coefficient (0.9) was found to be highly significant at P < 0.01 level, that indicated good opportunities for simultaneous genetic improvement of both iron and zinc contents in pearl millet

    (3E,5E)-1-Benzyl-3,5-dibenzyl­idenepiperidin-4-one

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    In the title compound, C26H23NO, C—H⋯O hydrogen bonds generate a ribbon structure along the a axis. These ribbons further assemble into a one-dimensional sheet parallel to the ac plane via C—H⋯π inter­actions. The piperidin-4-one ring adopts a sofa conformation with the 1-benzyl group in the equatorial position, and the 3- and 5-phenyl substituents stretched out on either side. The benzyl­idene units adopt E configurations and the 1-benzyl group is disposed towards the 3- substituent of the piperidin-4-one ring

    Interrelationship Among Biomass Related Traits and Their Role in Sweet Sorghum Cultivar Productivity in Main and Ratoon Crops

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    Increased global interest in biofuel feedstocks made sweet sorghum as one of the prominent energy crop suitable for both first and second generation biofuel production. An attempt has been made to critically identify the factors contributing to biomass yield and their interrelationship in sweet sorghum plant (main) and ratoon trials. The genotypes ICSSH 28, ICSSH 58, ICSA 749 × SPV 1411, B-24 and ICSV 93046 exhibited higher ratooning efficiency. It was observed that higher the ratooning efficiency lower will be the difference between the growing degree days (GDD) of main and ratoon crop. GDD can be used as one of the selection criteria in breeding programs aiming for enhanced biomass and ratooning efficiency
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